Chevrolet unveiled the new 2004 Aveo, the manufacturer's new product in the entry-vehicle segment; and the return of the Impala SS at the Chicago Auto Show. The Aveo lineup will include a pair of subcompact models -- a four-door and five-door. The Aveo features a 1.6-liter dual overhead cam 16-valve inline four-cylinder that delivers 105 hp and 107 lb.-ft. of torque. A large intake resonator and dual-muffler exhaust systems help reduce engine noise, and roller-type hydraulic lifters and a rubber timing belt help reduce the need for routine maintenance. The Aveo five-door features a rear-seat that folds and flips forward, creating a cargo area; and the four-door features a 60/40 split folding backseat for easier transport of bulky items. The automaker says the vehicle will arrive in showrooms by early 2004. The Impala SS will return to the Chevrolet lineup as a 2004 model, the company announced at the Auto Show. The vehicle will feature the 3800 Series II supercharged V-6, a 3.8-liter engine that generates 240 hp at 5200 rpm and 280 lb.-fot. of torque at 3600 rpm. The Impala also boasts a comprehensive safety package, room for five, and cargo space. The 2004 Impala SS will be built at the Oshawa No. I Car Assembly Plant in Ontario.